It looks like we got whacked by some SQL-injection bug, with the result that all signatures turned into php nonsense. I've been able to clear that out for a bunch of people, but it has to be done by hand. The result is that the signature is totally cleared out, I'm afraid.

Annis, the symptom was that I got a blank page in my browser. A few minutes later I was able to update my profile, including my signature. Most probably it was your administrative save which helped me, many thanks. All is well now.